“I have copious amounts of energy,” said Grammy Award-winning mezzo-soprano Anne Sofie von Otter during a recent phone interview from her home in the Swedish countryside, “And I’m very thankful for that asset.” The answer comes in response to the question of how the celebrated singer continues to stay in demand, while maintaining a a seemingly tireless performance schedule as diverse as it is ambitious.

The first half of 2015 sees the intrepid Swede starring in a new production of Kurt Weill’s Rise and Fall of the City of Mahagonny at London’s Royal Opera House, appearances as Waltraud in Götterdämmerung in Vienna, and the premiere of a new work by Hungarian composer Péter Eötvös with the New York Philharmonic. And those are just a few of the highlights.

Yet von Otter is beginning 2015 with the kind of unique collaboration she enjoys, a five-city North American recital tour of German and French song with award-winning pianist Angela Hewitt. The tour kicks off at Toronto’s Royal Conservatory Friday night, 9 January 2015, and continues to Mandel Hall in Chicago Sunday afternoon, as part of the University of Chicago Presents series. Subsequent concerts will be given in intimate venues in Boston, New York City and San Francisco.

The tour is the product of a well-received concert given by the pair during Hewitt’s Trasimeno Music Festival in Umbria, Italy in 2012. “I like working with Angela. She’s very quick, and very musical, so I thought ‘Why not, let’s go for it,’” said von Otter of the decision to reunite for a multi-city tour. Hewitt agreed. “I’m so happy it has worked out,” said the Canadian pianist. “We don’t have a hard time feeling the music in the same way. It is all very natural and comes easily.”

“It’s not so usual to have two ladies on stage, one playing the piano and one singing,” added von Otter. This is particularly rare for the singer, who is usually seen in concert with keyboard collaborator Bengt Forsberg, with whom she has worked since 1980.

Hewitt is a worthy partner for the established mezzo. An acclaimed interpreter of Bach – The Guardian referred to her as “the pre-eminent Bach performer of our time” – her sizable discography reveals a penchant for both impressionistic French song and Romantic German repertoire, both of which appear on the concert program. Works to be performed include art songs selected by the singer, as well several solo piano pieces chosen by Hewitt. “A pure lieder recital is not my thing,” said von Otter. “I like to have the pianist or another instrumentalist join in and do solos.”

The first half of the concert will feature German repertory by Brahms, Beethoven and Schubert, including well-known Romantic lieder such as Schubert’s tender Im Abendrot, and Brahms’ Von ewiger Liebe. The second moves into Francophone territory, musical terrain that both von Otter and Hewitt are taken with. Pieces to be performed include works by Fauré, Debussy, Chabrier, and the infrequently heard female composer Cécile Chaminade.

Although von Otter is widely considered one of the top lieder interpreters of her generation, her calm speaking voice becomes animated as she discussed the final set of songs by Chaminade. “I can’t wait to do those!” she exclaimed. “They are so lovely and charming that I’m really having fun practicing them now.”

Chaminade’s late-Romantic period art song remained largely forgotten until von Otter and Bengt Forsberg recorded the album Mots d’Amour in 2002. Her songs will be placed after three pieces from Debussy’s steamy Chansons de Bilitis song cycle, and von Otter cites the complementary nature of both sets. “It is very nice to show the width between the very impressionistic Debussy and the Chaminade songs coming up at the end. They are very, very different, and yet both composers are wonderful.”

Hewitt, too, expressed enthusiasm for the lesser-known piano works she will present. “I have a particular fondness for the two works of Chabrier, Idylle and the Bourrée fantasque, which I played when I was a young student. They are not as well known as they should be, and are full of charm.”

In the days leading up to the New Year, a time when most of us direct our attention primarily to digesting oversized holiday meals, von Otter is focused on preparing herself for the tour and the remainder of the season. “I have a break now, so I’m working several hours every day to try to prepare the voice for what’s coming up,” she said. “There is a lot of diversity in my repertoire and what I need is time to prepare it really thoroughly so it’s all very well worked into my voice.”

This attitude is at the crux of the singer’s secret to success: hard work. “When I was very young I could switch from Korngold to Monteverdi from one day to the next.” Now, she says, practice becomes increasingly essential. “Singing is like any sport. You can’t just go and do the high jump or a marathon unless you really practice, and with age that becomes more and more important.”

This healthy dose of realism is likely what keeps von Otter perfecting songs and learning new roles at an age when many of her peers begin to show signs of vocal fatigue.

Another of von Otter’s admirable attributes is her willingness to strive for mindful improvement. “When I was in Chicago in the fall singing at the Lyric Opera [as Clairon in Strauss’s Capriccio], I took some lessons with Julia Faulkner who used to be a colleague of mine. I always liked Julia and found that she had a lot of students, young artists of the Lyric, who sang very well. She’s now at the very back of my mind, like ‘What would Julia tell me?’”

The daughter of a Swedish diplomat, von Otter spent her youth in Bonn, Stockholm and London. She studied voice in her native Stockholm and at London’s Guildhall School of Music and Drama, before embarking on a fruitful three-decade career in leading opera houses and recital halls the world over. Tall and endowed with a natural grace, von Otter has sailed effortlessly into Hosenrolle and other mezzo faire, while maintaining a busy schedule of recital and soloist engagements, recording dozens of albums for Deutsche Grammophon, and more recently, her current label, Naïve.

Von Otter also has a penchant for collaborating with other artists and is not afraid to venture beyond the classical milieu. She has recorded an album of ABBA covers and collaborated with the likes of pop legend Elvis Costello and jazz pianist Brad Mehldau.

With ambitious plans for the 2015-16 season, including a production of TheThreepenny Opera in Vienna, the energetic singer shows no signs of slowing down. “On the contrary, I may as well keep my nose to the grindstone,” she says cheerily. “Eventually I’ll have to stop and think about teaching, or doing master classes or perhaps getting a dog.”

Until that time comes, there are roles to be learned, recordings to be made and plenty of art songs to be sung.